Pre-Christian Estonians used to worship their pagan gods at the Sacrificial Stone, a large boulder on the north side of the cathedral. This is one of about 400 sacrificial stones scattered around the country where (typically bloodless) sacrifices were made. And the sacrifices continue - nowadays, as a cathartic way to end the academic year, students burn their lecture notes here after exams. Behind the stone is the romantic Kissing Hill, where newlywed grooms are supposed to carry their (hopefully thin) brides. The padlocks you see clamped to the rails at the top are part of a Russian newlywed tradition, the locks symbolising the bonds of matrimony.